tuning sql server

Label:A recent project involves data-table queries of large data volumes. The total data table is about 700 million-2 billion, the primary key to establish a global unique index, the partition policy is hash partition + range partition, most of the time the query condition hit record more than million, a single return to the previous XX record. The following experiences are summed up in the tuning process:(1) Minimize the interval limit, even if the a

DB2 tuning SQL Execution Analysis I have always had a misunderstanding that it is the same to not creating indexes for all the fields in the table. Therefore, when the data volume reaches 1 million in a practical application, the retrieval speed is obviously slow, and the CPU usage during query execution is very high, which affects other jobs and leads to chain reactions.After discussing with some friends,

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One of the practical skills that can greatly improve the performance of SQL TUNING optimization. When we perform SQL optimization, we often encounter the need to sort a large number of datasets and then retrieve the first part of the results from the sorted set. In this case, when we write SQL statements according to t

Web applications with more than 300 million data records in a single tableProgramAfter the test, some functional and performance problems were discovered. The following methods were taken to adjust the performance: Changing the vast majority of SQL queries to stored procedures can undoubtedly improve some performance. All operations that use "select * from XXX" are specific to the required fields. Join is used to connect more than two tables

First, manually generated SQL Tuning Advisor1. SQL Text Format:DECLAREMy_task_name VARCHAR2 (30);My_sqltext CLOB;BEGINMy_sqltext: = ' SELECT * from dba_segments WHERE owner= ' CLIC ' and segment_type= ' TABLE ';My_task_name: = Dbms_sqltune. Create_tuning_task (Sql_text = My_sqltext,Scope = ' comprehensive ',Time_limit = 60,Task_name = ' Test_sql_tuning_task1 ',De

The SQL Tuning toolset (SQL Tuning set,sts) is an integral part of the Oracle 10g SQL Tuning Advisor feature. Each tuning toolset contains one or several

union and UnionAll. UnionAll Good 18, pay attention to using distinct, do not use when not necessary, it will make the query slower than the union. Duplicate records are not a problem in the query. 19. Do not return rows or columns that are not required when querying 20. Use sp_configure ' query governor cost limit ' or setquery_governor_cost_limit to limit the resources consumed by the query. When an estimate query consumes more resources than the limit, the

The BIOS defaults to a good balance between performance and power consumption when the server is shipped to the general environment, but in a high-load environment, it is necessary to optimize the server without the need for energy-saving mode (720xd machine load to 20+ to self-hang) for maximum throughput or the lowest latencyThe following are configuration adjustments for the Dell R710* You can test your

, according to explain optimization; b. When there is an order by A.col condition, all joins must be left joins, and Each join field creates an index, and the Where condition can only have a table condition, the data associated with the other table is formed into a large table in a, then the complete set of a is filtered; If you cannot use the left join entirely, you need to use it flexiblyStraight_join and other techniques, take the time sequence as an example: 1) Data warehousing Accordi

summary data is based is updated frequently, it is easier to use a view than to write SQL every time 2. Create a ViewThis is how the CREATE view is defined in the MySQL documentation: CREATE [OR REPLACE] [algorithm = {UNDEFINED | MERGE | TempTable}] [definer = {User | Current_User}] [SQL SECURITY {definer | INVOKER}]VIEW view_name [(column_list)]As Select_statement[With [cascaded | LOCAL] CHECK

Tags: mysql new master-slave promotion from the mainThe day before yesterday to customers to do a database server adjustment, the previous one host abandoned, one from the library to promote the main, and then new to join other slave, here to record the operation steps:First, the old master library is turned on for read-only so that later steps are rolled back: Flush tables with read lockSecond, 110.10.1.102 upgrade to the main library, pause synchron

Tags: nts BSP One execution plan ext CSDN Pull performance issues Recently because very busy, has been busy to develop the company's products and customer affairs, assorted, busy, so, for a long time did not come here to write things, this two days for the customer optimized a system, optimize the CPU continued hoisting full, leading to the system card, the application system can not be used normally, There is a SQL execution plan is a bit large

fromV$thread T, V$parameter vWHEREV.name= 'Thread' and(V.value= 0 ORt.thread#=To_number (v.value))) I, (SELECTVALUE fromV$parameterWHERENAME= 'user_dump_dest') D;3.2 Using the Tkprof command to beautify the generated trace fileHere is what I often use, for more detailed instructions on the tkprof command, you can see the tkprof command directly enter.Tkprof xxx.trc xxx.txt Explain=system/Oracle sys=nReference URL: http://www.eygle.com/archives/2004/10/use_sql_trace_to_diagno

1. Disable IPV6netsh interface teredo set state disabled netsh interface 6to4 set state disabled netsh interface ISATAP set state disable D2. Disabling Event Tracker Click Start, and then click Run. Type gpedit.msc, and then click OK. Expand Computer Configuration, click Administrative Templates, and then click System. Double-click Show Shutdown Event Tracker. Click Disabled, and then click OK. 3. No need to press Ctrl+alt+del Click Start, and then click Run. Type g

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, faster disk.2.5.1. Network performance evaluation（1）通过ping命令检测网络的连通性（2）通过netstat –i组合检测网络接口状况（3）通过netstat –r组合检测系统的路由表信息（4）通过sar –n组合显示系统的网络运行状态Three Linux server performance Tuning 1. Tuning the Linux kernel elevator algorithm for disk I/OWhen the file system is selected, the algorithm balances low latency requirements, collects enough data, and effectively or

Use of the 1.explain plansql> explain plan for delete from T_jingyu; Explained.sql> select * FROM table (dbms_xplan.display); Plan_table_ OUTPUT------------------------------------------------------------------------------------------------------------------- -------------------------Plan Hash value:1368587462------------------------------------------------------------- ----------| Id | Operation | Name | Rows | Cost (%CPU) | Time |--------------------------------------------------------------

1. Import the trace file into the tableSELECT IDENTITY (BIGINT11 as RowNumber,* into TableNamefrom fn_trace_gettable ('trace.trc'default)2. Querying for statements with large CPU overheadSELECT Top -Total_worker_time/Execution_count asAvg_cpu_cost, Plan_handle, Execution_count, (SELECT SUBSTRING(text, Statement_start_offset/2 + 1, ( Case whenStatement_end_offset= -1 Then LEN(CONVERT(nvarchar(Max),text))* 2 ELSEStatement_end_offsetEND -Statement_start_offset)/2) fro

Select * from Table (dbms_xplan.display_cursor (sql_id = ' 9s7pt2ay4t3jg '));DeclareL_result_name Varchar2 (30);L_task_name Varchar2 (£): = ' task_name_9s7pt2ay4t3jg_1 ';L_sqlid Varchar2 (£): = ' 9S7PT2AY4T3JG ';BeginL_result_name: = Dbms_sqltune.create_tuning_task (sql_id = L_sqlid,Scope = ' comprehensive ',Time_limit = 60,Task_name = L_task_name,Description = ' Task to tune a query on a specified table ');Dbms_sqltune.set_tuning_task_parameter (Task_name = L_task_name,Parameter = ' Time_limit